Egg yolk antibodies (IgY) and its relevance in animal and human health-An updated review

Abstract

Egg yolk represents an alternate source of antibody and provides some advantages over mammalian serum immunoglobulins. The principal immunoglobulin in avian blood is Immunoglobulin Y (IgY) and is transferred to egg yolk and then to their offspring and thus makes it possible for the non-invasive harvesting of antibodies in higher amount from eggs. Moreover, due to the structural differences and phylogenetic variations, IgY is more acceptable than mammalian antibodies for diagnostic purposes, as it does not interfere with mammalian antibodies and shows greater avidity for proteins retained in mammals. As a therapeutic and diagnostic tool, IgY has wide application in animal and human health. The emergence of drug resistance organisms causing respiratory tract infections is a critical problem for the health care system worldwide. Passive immunization is a potential alternative for this. Recent studies on the diagnosis and therapeutic effects of IgY against SARS-CoV-2 indicates the importance of this technique in the present context. This review refers to the use of IgY antibodies from chicken egg yolks against the infection caused by bacteria, viruses (including SARS-CoV-2) and parasites in human beings and in animals in addition to its use in food preservation, anti tumour and anti allergic activities. Keywords: Egg yolk antibodies (IgY); human health; SARS-CoV-2; Egg yolk